It's very rare that the max speed in any given speedometer is equal to the max speed of the vehicle itself, maybe the max speed is indicated by a red needle for example
The speedometer in the HUD goes up to 300km/h which far exceeds the maximum speed of the train, so it is an issue. In service you can only go to 160km/h, and the train isn’t capable of going much faster than that. I think in TSW2020 the HUD speedo went up to 200km/h or something more appropriate to the train.